/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.spark.sql.execution.datasources

import org.apache.spark.SparkEnv
import org.apache.spark.sql.internal.oap.OapConf
import org.apache.spark.util.Utils

object ExternalDBClientFactory {

  private var instance: ExternalDBClient = null

  def getDBClientInstance(sparkEnv: SparkEnv): ExternalDBClient = synchronized {
    if (instance != null) return instance
    instance = Utils
      .classForName(SparkEnv.get.conf.get(OapConf.OAP_EXTERNAL_CACHE_METADB_IMPL))
      .getConstructor()
      .newInstance()
      .asInstanceOf[ExternalDBClient]

    instance.init(sparkEnv)
    instance
  }

  def destroyDBClientInstance(externalDBClientInstance: ExternalDBClient): Unit = {
    externalDBClientInstance.stop()
  }

}
